Conventionally, as such a management server device, there has been widely known a technology which manages a physical machine such as, e.g., a host machine and, at the same time, manages a plurality of virtual machines implemented on the physical machine using virtualized software, and allows arbitrary virtual machines among the plurality of virtual machines to cooperate with each other to execute one control process.
In addition, as such a management server device, there has been widely known a technology which stores state information on each virtual machine and executes halt and resumption of the virtual machine (for example Japanese Patent Laid-Open No. 2001-5679).
In accordance with the conventional management server device mentioned above, for example, when a plurality of virtual machines implemented on a physical machine are managed using virtualized software, and a halt instruction is given to one virtual machine among the plurality of virtual machines in cooperation with each other, the virtual machine is halted, and when a resumption process is executed with respect to the halted virtual machine, the halted virtual machine is resumed. However, in the case where a plurality of virtual machines cooperate with each other to execute one control process, even when one virtual machine among the plurality of virtual machines in cooperation with each other is halted, the virtual machines other than the halted virtual machine are still in operation. As a result, even when the halted virtual machine is resumed, there can be considered a situation where consistency can not be secured among the virtual machines in cooperation with each other.